Abstract: High yield and good quality embryos were obtained from cultures of isolated microspores of Brassica napus L. Cv. Global. The donor plants were grown in a growth chamber at 15/10°C (day/night) with a 16/8 photoperiod. Microspores were isolated from whole buds of 2.5-3.5 mm in length, containing late-uninucleate and early-binucleate microspores. Different heat shocks including, 30°C for 10, 14 and 18 days, 32°C for 2 and 3 days and 35°C for 18 h followed by 30°C for 10 days and various culture densities including 60,000, 40,000 and 20,000 microspores per mL were used. Results showed significant differences among the heat shocks, the culture densities and their interaction for embryo induction. The largest number of embryos was obtained from the microspores treated at 30°C for 18 days, 35°C for 18 h followed by 30°C for 10 days and 30°C for 14 days for a density of 60,000 microspores per mL.